Related papers: The Prototype of the Small Synoptic Second Solar S…
Due to the quick evolution of the solar chromosphere, its magnetic field cannot be inferred reliably without accounting for the temporal variations of its polarized light. This has been broadly overlooked in the modelling and interpretation…
Turbulent magnetic fields fill most of the volume of the solar atmosphere. However, their spatial and temporal variations are still unknown. Since 2007, during the current solar minimum, we are periodically monitoring several wavelength…
Recent theoretical investigations have pointed out that the cores of the Ly-alpha lines of H I and He II should show measurable scattering polarization signals when observing the solar disk, and that the magnetic sensitivity, through the…
Linear (spectro) polarimetry is usually performed using separate photon flux measurements after spatial or temporal polarization modulation. Such classical polarimeters are limited in sensitivity and accuracy by systematic effects and…
This article presents an introduction to optical pumping, atomic polarization and the Hanle effect in weakly magnetized stellar atmospheres. Although the physical processes and the theoretical framework described here are of interest for…
The magnetic field plays a major role in governing the dynamics of the sun. Many interesting features like sunspots, flares, prominences, and Coronal Mass Ejections (CMEs) occur on its surface due to the dynamics associated with the…
We demonstrate the use of an optimized 5 core photonic lantern (PL) to simultaneously measure tip/tilt errors at the telescope focal plane, while also providing the input to an instrument. By replacing a single mode (SM) fiber with the PL…
The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, multi-color, millimeter-wave, bolometer camera. It is located at the Amundsen-Scott South Pole station in Antarctica. The design of…
We are developing an X-ray polarimeter using micro-pixel CMOS sensors for solar flare X-ray polarimetry. The system consists of a 2.5-$\mu$m pixel CMOS image sensor with a 12.8$\times$12.8 mm$^2$ imaging area and a readout system based on a…
Is it physically feasible to perform chromospheric diagnosis using spatial maps of scattering polarization at the solar disk center? To investigate it we synthesized polarization maps (in 8542 Angstroms) resulting from MHD solar models and…
Context: Polarimetry is a very powerful tool to uncover various properties of astronomical objects that remain otherwise hidden in standard imaging or spectroscopic observations. However, the reliable measurement of the low polarization…
Scattering polarization in the Sr I 4607.3 \AA \ line observed with high resolution is an important diagnostic of the Sun's atmosphere and magnetism at small spatial scales. At present, spatially resolved observations of this diagnostic are…
Exposing the polarization signatures of the solar chromosphere requires studying its temporal variations, which is rarely done when modelling and interpreting scattering and Hanle signals. The present contribution sketches the scientific…
The sizable linear polarization signals produced by the scattering of anisotropic radiation in the core of the Ca I 4227 $\mathrm{\r{A}}$ line constitute an important observable for probing the inhomogeneous and dynamic plasma of the lower…
Aims: The polarization of the Ca II resonant doublet (H and K lines) and the subordinate infrared triplet lines are key observables for diagnosing solar chromospheric magnetism. It is thus necessary to understand the physical mechanisms…
We present observations of quiet-sun small-scale structures (SSS) in the microwave range with the {\it Radio Astronomical Telescope of the Academy of Sciences 600} (RATAN-600) spectral-polarization facility in a wide range of frequencies.…
The history of the IRSOL observatory is closely related to Second Solar Spectrum observations. Already in 1963 Brueckner observed scattering polarization in the CaI 4227A line. In 1996 the Hanle effect in the quiet chromosphere was measured…
In the last decade, imaging polarimeters based on micropolarizer arrays have been developed for use in terrestrial remote sensing and metrology applications. Micropolarizer-based sensors are dramatically smaller and more mechanically robust…
We present commissioning data for the POLISH instrument obtained on the Hale 5-m telescope. The goal of this high precision polarimeter is to constrain orbital inclination of high mass X-ray binaries and to therefore obtain independent mass…
In order to understand the heating of the solar corona it is crucial to obtain empirical information on the magnetic field in its lower boundary (the transition region). To this end, we need to measure and model the linear polarization…